Cowl



COWL

FildFeb. 24, 194i 4 sheets-sheet@ ATTORNEYS COWL Filed Feb.` 24, 1941 4 sheets-sheet 2 ATTORNEYS July 14, 1942.

F. A. woJclK COWL Filed Feb; 24, 1941 4 Sheets-Sheet 3 ATTORNEYS llge ffm/2 i l n, f2 109 F.l AI WoJclK 2,289,616

July 14, 1942.

cowL l Filed Feb. 24, 1941 4 sheets-smet 4 ATTORNEYS tative ring Patented July 14, 1942 UNITED STATES `PATENT OFP'fCE COWL Frank A. Wojcik, Indianapolis, Ind. Application February 24, 1941, Serial No. 380,380 3 Claims. (Cl. 123-171) My invention relates to the cooling of aircooled internal combustion engines of the type employed for the propulsion of airplanes.

An object of my invention is to provide an improved cowling of a streamlined design and provided with shutters adapted to be opened and closed in response to variations in engine temperatures for effectively regulating the Iiow of cooling air.

The present invention is particularly adapted to an engine of the radial type, and the cowling is provided with a series of shutters operatively connected with an actuating device which is thermostatically controlled for regulating the positions of the shutters in accordance with predetermined engine temperature conditions. The shutters are connected as a unitVA with the actuating mechanism, and a manual control is also provided whereby the shutters may be manually manipulated independently ofthe temperature responsive control system. y

In the accompanying drawings: l Figure 1 is an elevational Figure 2 is an enlarged sectional view taken along the line 2-2 of Figure 1;

Figure 3 is an enlarged longitudinal sectional view of the greater part of the cowling;

Figure'4 is a fragmentary perspective view of l one of the shutters illustrating one shutter hinge, there being two hinges for each shutter;

Figure 5 is a fragmentary perspective view illustrating a master bearing mounted on the nose section of the crank case and provided with a rohaving arm connections with the respective shutters for moving the latter to open and closed positions through rotation of the ring;

Figure 6 is a view taken from the position indicated by line 6--6 of Figure 1 and constitutes a top plan view of the ring, a fragment of which ring is illustrated in Figure 5;

Figure 7 is a sectional view along the line 'l--l of Figure 6; Figure 8 is an enlarged perspective view illustrating the hydraulic control circuit connected with the ring of vFigures 5 and 6, together with the manual control; l

Figure 9 is a top plan view of a hydraulic cylinder interposed in the hydraulic circuit for actuating the shutters, with a portion of the cylinder broken away for the sake of clearness;

Figure 10 is a sectional view taken substantially along the line Ill-I0 of Figure 9;

Figure 11 is a sectional view of .a thermostatil cally controlled valve which automatically opens and closes the hydraulic circuit for actuating the shutters, the thermostat of which valve is preferably located in the engine oil sump;

Figure 12 is a sectionalv View along the line l2|2 of Figure 11; and

View of thecowling;

22 extends through the crank case 20 for" connection with the hub 23 to which the propeller 24 is connected. My improved cowling 25 enloses the engine 2| and the crank case 20, `and the cbj y ward end of the fuselage shell cowling tapers noseward and a spinner 26 and a spinner preferably rubber covered. l

The forward end of the cowling 25 is riveted to a `flange 28 having a flange 29 fitting snugly the nose comprises cap 21. Cap 2l is about the forward end of the crank case 2li` and secured thereto by bolts 30. The rear end of the fuselage ts about a band 3| to which the for 32 is also securel iBoth the cowling and the shell 32 may be rvete l ,tothe band al, and the latter is provided wir an annular rib 33 `forreinforcing purposes.` .f

The cowling 25 is provided with a seriesfof air inlet openings 34 extending longitudinally of the cowling `throughout its greater length. To the inner side of the cowling 25 and adjacent each sidey edge of the openings 34 is secured a reinforcing T-member 35, which members constitute structural reinforcing elements for the cowling as well `as the fuselage shell. The cowling as well as the y shell 32 may be riveted to the members 35. Each opening 34 is provided with a shutter 36 which may completely close its respective opening as well as to uncover the opening in different-degrees, depending upon engine condition. Each shutter 36 is secured to the cowling 25 along one edge margin of the shutter. Fig. 4 best illustrates the manner in which the shutters are` hinged. The fragmentary shutter 36 in vthis View is offset .at 31 to provide a'flange 38 which extends completely about the perimeter of the shutter, and the flange 38 overlaps the inner face of the cowling 25 completely about its respective opening 34. All the shutters are identical in construction so that the description of one will apply to all.

. Fig. 4 illustrates one hinge connected with its respective sh'utter 36, which hinge includes a Y hinge part 39 riveted at 40 to the web 4| of the trates the relative spacing of the hinges associated with the shutters 36, and the taper of the cowling 25 is such that a straight line drawn through the axes of the hinges on a shutter will be arranged at an angle of 221/2 to the axis of the cowllng or shaft 22.

The crank case 20, see Fig. 5, is provided with a circumferential rib 45 upon which is mounted a band 46 which is provided with a flange 41 along one edge and a band 48'along the opposite edge, which flange and ,band are spaced to provide a bearing race for a ring 49.1` The band 46 is clamped against the rib 45 through the medium of screws'50 which pass through the band 48 and ,the band 46 and are threadedminto the rib 45.v Fig. 5 illustrates one of the screws`-A 50 and Fig. 6 illustrates the spacing of the screws.

Ring 49 rotates on the band 46 `and is restrained from lateral shifting by reason of the flange 41 and the band 48. Specifically, the ring comprises two sheet metal flanges 5| arranged face to face and each flange having a rightangular flange 52 bent back upon itself to provide a narrow flange 53 which rides on the band 46. The anges 5| are connected into a unitary structure through the medium of rivets 54. Flanges 5| are also provided with ears 55 spaced crcumferentially of the ring 49. The ears on one flange 5| lie face to face with the ears on the other flange so that each pair of ears constitutes a lug 56, with the number of the lugs equaling the number of shutters 36.

To each shutter 36 is riveted an attaching member 51 and each attaching member is connected with a tubular connecting rod 58 through the medium of a universal joint 59, and each connecting rod 58 has its other end connected with one lug 56 through the medium of a universal joint 60. Figs. 2 and 8 best illustrate the arrangement of the connecting rods. The connecting rods 58 are connectedmith their respective shutters 36 at the center of pressure of the shutters when the latter are in closed positions. The shutters are opened through rotation of the ring 49, which rotation causes the connecting rods to exert a pull on the shutters and swing the latter to open positions about the axes of their respective hinges.

Means for rotating the ring 49 for opening and closing the shutters 36 comprises a cable 6| Ahaving one end connected with a coupling member 62 riveted to the flanges 5|, see Fig. 6. The cable passes around a grooved wheel 63 supported by a bracket 64 mounted on the crank case 20 and /around a grooved wheel 65 rotatably mounted on a coupling member 66, see Figs. 6, 8 and 10, which coupling member is threadedly connected with one end of a piston rod 61, as in Fig. 10. In Fig. 6, the opposite end of the cable 6| is connected with an eyev 68.

A second cable 69 has one end connected with a coupling member 10 riveted'to the flanges 5|, see Fig. '1, and the cable passes around a grooved wheel 1| carried by a bracket 12 attached to the crank case 20. The cable 69 extends rearwardly of the crank case 20, see Fig. 8, and passes around a grooved wheel13 carried by a bracket 14 secured to the crank case. From the pulley 13, the cable 69 passes around a grooved wheel 15, another grooved wheel 16 and a grooved wheel 11 which may be rotatably mounted on any suitable sup-- port within convenient reach of the attendant, and the wheel is provided with a handle 18 to facilitate rotation thereof. From the grooved wheel 11 the cable 69 passes around a grooved wheel 19 associated with the wheel 16 and both i Wheels are rotatably carried by a clevis 80 connected with a tension spring 8| also secured to a bracket 82 which may be xedly connected with any suitable support on the craft. From the grooved wheel 19 the cable 69 passes around a grooved wheel 83 associated with the wheel 15 and is then connected with a fixed post 84. Wheels 15 and 83 are rotatably carried by a clevis 85 best illustrated' in Figs. 8 and 10. The clevis 85 is threadedly connected with the opposite end of the piston rod 61.

Piston rod 61 extends through stufng boxes 86 at the ends of a cylinder 81 having lugs 88 bolted to the crank case 20. Thus the piston rod/61`slidably extends through the stuffing boxes 86 and reciprocatory motion of the piston rod is converted into rotary motion of the ring 49. Fig. 8 illustrates the shutters 36 in closed positions and rotation of the ring 49 in the direction of the arrow 89 exerts a pull on the connecting rods 58 and simultaneously moves the rods and shutters 36 to the dotted line positions of Fig. 2.

Rotation of the wheel 11 ina counter-clockwise direction when viewing Fig. 8 exerts a pull on the end of the cable attached to the post 84 for moving the piston rod 61 to the positions of Figs. 8 and 10, at which time the ring 49 is rotated for fully closing the shutters 36, since the cable 6 I, is attached to a fixed eye at one end and to the ring 49 at its other end. Similarly, clockwise rotation of the wheel 11 exerts a pull on the cable 69, particularly the end of the cable attached to the ring 49 for rotating the ring in a clockwise direction when viewing Fig. 8, which rotation of the ring moves the shutters to an open position. Such actuation of the cable 69 causes the piston rod 61 to be shifted to its opposite extreme position, since the cable 6| is attached to the ring 49 and this cable will be pulled by the ring as the ring is rotated by reason of the pull on the cable 69. A piston 90 is mounted on the piston rod 61 inside the cylinder 81, which piston divides the cylinder into chambers 9| and 92 having communication one with the other by reason of a bypass pipe 93 provided with a valve 94 which may be manually adjusted to open and closed positions. When the valve 94 is opened, the piston 90 may move freelyinside the cylinder 81 since fluid displaced from one chamber is transferred to the other.

chamber.

Valve 94 is provided with an arm 95 connected with an operating wire 96 slidable in a spiral housing 91, which wire is provided with a knob 98 to facilitate manipulation of the Wire, see Figs.

The automatic shutter operating mechanism comprises pipes 98 and 99 which respectively communicate with the chambers 9| and 92. These pipes connect with the body |00 of a thermostatically controlled valve IDI. The body |00 is provided with a bore |02 within which is rotatably disposed a Valve |03 having a shaft |04 fixed thereto and connected with one end of a bimetal spring |05 having its other end attached to a pin |06 carried by a bearing base |01 which may be made secure inside the engine oil sump so as to make the spring |05 responsive to the temperature of the oil in the sump. Bearing' base |01 is provided with openings |08 for the reception-of bolts (not shown) which may be utilized for anchoring the base.

Valve |03 is provided with two grooves |09 and H9, and the body |00 is provided with ports ||2, ||3 and ||4 which lie in a common plane and in the plane of the grooves |09 and I0. Pipes 98 and 99 are attached to the valve body |00 through the-medium of coupling elements H5, and the pipes respectively communicate with th portsH2andHl.

Fig. 12 illustrates the plug |03 adjusted to a position which locatesthe groove H for placing the ports H`| and H3 into communication.

` Grooves |09 and ||0are isolated one from the other so that neither groove can have communication with the other. is connected pipes H5 and H6 which communi- To` the valve body |00A cate with an oil sump or reservoir tank H1. An

oil pump H8 is interposed in the pipe H5, which oil pump may comprise one of the oilpumps of the engine. Fig. 12 illustratesl the pipe 'H5 as being connected with the body |00 through the medium of a coupling element H9, and the pipe communicates with the port I4. Similarly, the pipe H6 is `attached to the body |00 through the communicates with the port H3.

With the valve |03 positioned according to Fig. 12, oil in the pipe and pump system willbe medium of a coupling element |20, and the pipe forced into the port H4, through the groove |09 i and into the pipe 98 which forces the piston 90 of Fig. 10 to the position shown: therein. VAt the 1 .same time, pipe 99 communicates with the port H and with the pipe 6 through the medium of the groove H0 andthe port H3 so that oil from the chamber 92 in the piston may be returned to theY reservoir H1. The valve |03 is controlledV through the action of the bimetal spring |05.,V 1 Rotation of the valve in a clockwise direction ance, and the engine nose section length is slightly greater than the conventional engine nose section, this diierence providing the unobstructed depth needed for the inward and backward action of the shutters. The cowling is devoid of abrupt obstructions immediately in the rear of the propeller blades.

The shutter action is regulated through the medium of the oil temperature of the engine. The automatic control is so arranged that there is no fixed relation between the engine temperature Vand the amount of shutter opening. Such an arrangement provides for the ever-changing atmospheric temperature.

The shutters are of elongated contour with respect to the line of ilight so that the hinge lines are set at small angles to the line of flight. This` arrangement permits thel incoming `air to enter the cowling practically undisturbed, thus keeping the surplus cooling `air from disturbing the air flow around the nose of the Cowling. The number of shutter openings in the cowling is equal `to the number of cylinders in the engine for which a particular cowling is designed. This arrangement gives each cylinder an individual center opening.

Having thus described certain embodiments of my invention in detail, it is, of course, understood that I do not desire to limit the scope thereof to the exact details set forth except insofar as those details may be defined in the appended claims.

I claim: 1. In combination, a plurality of shutters circularly disposed and each pivotally mounted upon a generally longitudinal axis and spaced `one from .the other, a crankcase, said crankcase being elongated to provide the unobstructed space required by the inward and backward action of the shutters, a circumferential rib integrally mounted around said crankcase, a ring, said ring being rotatably mounted around said circumferential rib, connecting rods between said shutters and said ring for simultaneously advancing the shutters when the ring is rotated in one direction and for simultaneously receding the shutters when the ring is rotated in the opposite direction, a servo-motor, a `plurality of cables connecting said ring and said servo-motor for converting the reciprocating action of the servo-motor to rotative action of the ring, a fluid circuit, pipes operatively connecting fluid circuit with said servomotor, a valve interposed in` said fluid circuit for reversing the action of the servo-motor, an oil sump, and a temperature responsive element located in said oil sump and operatively connected with said valve for actuating the latter. 2. In combination, a plurality of shutters circularly disposed and each pivotally mounted upon a generally longitudinal axis, a crankcase, said crankcase being elongated to provide the unobstructed depth required by the inward and backward action of the shutters, a circumferential rib integrally mounted around said crankcase, a ring, said ring being rotatably mounted around said circumferential rib, connecting rods between said shutters and said ring for advancing the shutters when the ringis rotated in one direction and for receding the shutters when the ring is rotated in the opposite direction, a servo-motor, said servo- `motor having a by pass valve providing for actuating the servo-motor manually, a plurality of cables connecting said ring and said servo-motor `for converting the reciprocating action of the servo-motor to rotative action of the ring, a fluid circuit, pipes operatively connecting iiuid circuit with said servo-motor, a valve interposed in said fluid circuit for reversing the action of the servomotor, an oil sump, a temperature responsive element located in said oil sump and operatively connected with said valve for actuating the latter and a manual control operatively connected with said servo-motor for advancing and receding said shutters independently of the oil temperature in said oil sump. y

3. In combination, a plurality of shutters circularly disposed and each pivotally mounted upon a generally longitudinal axis to swing towards and away from the axis of a circle, a crankcase, said y crankcase being elongated to provide the unobstructed depth required by the inward and back--v ward action of the shutters, a ring, said ring being rotatably mounted around said crankcase, connecting rods between said shutters and said ring for advancing the shutters when the ring is rotated in one direction and for receding the shutters when the ring is rotated in the opposite direction, and means manually operating said ring, said means including a plurality of cables connected at one end to said ring and at the other end to a wheel.

l FRANK A. WOJCIK. 

